I've also read in firearms litterature since I was a kid that the Villar-Perosa was the "ancester" of all SMGs, at least the concept thereof (an individual automatic weapon firing the ordnance pistol cartridge).

The Villar Perosa was NOT an "individual" weapon. In today's point of view, it would. With then point of view of World War 1, no automatic weapon could be "individual" only squad support.

__________________
"It is criminal to teach a man not to defend himself, when he is the constant victim of brutal attacks. It is legal and lawful to own a shotgun or a rifle. We believe in obeying the law." -- Malcolm X

"We (atheists) act in good conscience because we believe in moral principles, not because we expect a reward in Heaven." -- Margherita Hack

Well, I guess the pistol ammo factor was preponderant in the various writers' minds to make it the SMGs forefather...

Of course now it is categorized as an SMG (which I agree) for its pistol-caliber chambering. But it was made as a squad machinegun, and not even that! Actually, the first use of the "Villar Perosa" which came to Beretta and FIAT engineers' mind when they made it was to mount it on airplanes for the air fight. At the time, airplanes were made mainly of paper and light wood, and fought each others at very close distances. So such a weapon, in the hands of an aircraft machinegunner, should have turned out very effective. I say that it SHOULD HAVE, because in the truth the .9mm-Glisenti cartridge was desperately poor in power for that purpose. The "Villar Perosa" was subsequently distributed within Italian ground troops fighting against Germans and Austrian-Hungarian troops during World War 1, again as a squad support weapon. The fact that it fired pistol cartridges and was very lightweight for a machinegun made the commanders thought that it had to be the ideal support weapon for the assaults and close range trench shootings of World War 1 (imagine that they would have wanted it to become the correspective of that time of the nowadays' M249-SAW). But again, the .9mm-Glisenti is an incredibly weak cartridge, good only for general officers' personal defense sidearms. And even if it was light to transport, the "Villar Perosa" required three men to be transported (one for the gun itself, one for the tripod, one for the box of loaded magazines), and was not usable when not mounted, because every one of the two barrels had separate triggers, and because it fired at a very high velocity, making it impossible to control if not placed on a tripod and very VERY inaccurate.

The "Villar Perosa" was a failure for all the intents and purposes it was made for. It is interesting to think, anyway, that the Beretta and FIAT engineers who conceived it were one step ahead from making a great gun. A "single-barrelled Villar Perosa" is in fact the perfect submachinegun. When they made the MAB, all they did was to pick up one single "Villar Perosa" barrel, invert its feeding system into downside feeding and side ejection, replace the trigger system with a standard rifle trigger (two triggers, one for single-auto, another for burst fire) and place it on a standard wooden rifle stock. But I guess the things went mature at the right time. The first Army actually to employ a submachinegun was the German one, distributing the MP-18. But even the Germans distributed it as a squad support weapons for "Sturmtruppen" (special assault troops tasked to lead the way into bloody assaults to enemy trenches), MP-18s were issued in the number of 1 or 2 per platoon, and were used EXACTLY like today most Armies (including the US and Italian ones) use the "MINIMI" M249-SAW. The Germans even assigned to every MP-18 operator a second soldier to carry the ammunitions.

__________________
"It is criminal to teach a man not to defend himself, when he is the constant victim of brutal attacks. It is legal and lawful to own a shotgun or a rifle. We believe in obeying the law." -- Malcolm X

"We (atheists) act in good conscience because we believe in moral principles, not because we expect a reward in Heaven." -- Margherita Hack

Ditto. You think a 7.62 NATO minigun is somehow lacking in hitting power? Do you have any idea how much MORE hitting power it has than .357? Not to mention range.

And even if you were going with a magnum pistol round... why .357? 10mm Auto is the magnum class round for autoloading. And it even has "lite" loading variants and heavy loads for quite a range of potential.

Even so, for the size and weight of this kind of thing, a rifle cartridge is better. A 6.5 Grendel minigun could be amazing... better range than a 7.62 NATO gun, plus higher effectiveness against light armor, similar effectiveness against infantry, siginificantly lower recoil, and weight savings in gun and per round weight that leads to a lot more ammo carried. That can be a big deal for helicopter and infantry applications. That's why some of us are crazy about the 6.5 round, it can actually exceed 7.62 NATO in many applications, and mostly match it in most others, all with less weight and recoil. That's win-win-win.

As for the belt, have you ever considered just using a non-disintegrating belt and arranging the feeds so that each barrel is always fed from a different index? When you initially load the belt you'd have a handful of rounds wasted, but it's not like ammo wastage of a few bullets is a concern with this kind of idea. The belt would be like this:

1-2-3-1-2-3-1-2-3-1-2-3-1-2-3

Where each number represents the barrel that's going to feed from that spot. The belt needs to be held together til the last barrel to maintain the indexing though. If it was to disintegrate, it would need to be broken apart by something other than simply having bullets pulled out. But if needed, a "belt breaker" of some kind could disassemble the belt by some other mechanic after the last barrel.

Many gamers who have a little bit of grip on reality as far as it concernes guns are fixed on Magnum-caliber machineguns (.357-Mag or .44-Mag) because they think it's the way to realize their dream of a man-portable individual weapon "Minigun", like the one that appears in the movie "Predator", in the videogame "Doom", etc.

Let's just break their hopes down because it's too late, guys. Man-portable, individual Minigun = IMPOSSIBLE. Now and ever.

__________________
"It is criminal to teach a man not to defend himself, when he is the constant victim of brutal attacks. It is legal and lawful to own a shotgun or a rifle. We believe in obeying the law." -- Malcolm X

"We (atheists) act in good conscience because we believe in moral principles, not because we expect a reward in Heaven." -- Margherita Hack

Let's just break their hopes down because it's too late, guys. Man-portable, individual Minigun = IMPOSSIBLE. Now and ever.[/quote]

True, They are too heavy, Clumbersome and Thirsty on Ammo but i quite find this 'Handheld Nordenfelt' or 'Ripper Chaingun Cannon (RCC)' a substitute for a 'HandHeld Minigun'. I suppose 6.5 Grendel Rounds would be ideal for this
but i liked the thought of a .357 Magnum Round fired at a high ROF.

Maybe this RCC could fire belted 10mm/.50AE rounds but at a ROF of 1,700 RPM?

OK... looking at your feed, it's impossible. Sorry, wouldn't work. The gear to pull the bullets out would likely be too close together, and the chambers almost certainly would be to close together to be safe.

I had figured on each chamber being about 3 bullet widths apart. Like this:

How much range would you think this thing should have? Its accuracy is going to be HORRIBLE if it is fired without a support.

If you really just need to put swarms of projectiles in the air really quick, at shorter ranges, get an auto shotgun. It's a lot more practical, and you won't shoot the rifling out of the barrel either. And an auto-seared Saiga 12 with a 20+ round drum, loaded up with flechette sabots, definitely has a lot of lethality, range about like an SMG, and puts a lot of projectiles in the air in a hurry.

As for calibers, you seem to have little comprehension of the difference between pistol cartridges and rifle cartridges and just how significant the gap is.